In triangle ABC, AC=13, BC=84, and AB=85. Find the measure of angle C

Bob is putting books on a shelf and takes a break after filling 18 1/2 inches on the book shelf. the book shelf is now 2/3 full. how long is the entire bookshelf?

Select all the statements that apply to this figure

Last week , donnell practiced the piano 3 hours longer than marcus . together, marcus and donnell practiced the piano 11 hours . for how many hours did each young man practiced the piano